Products Description

 

Product name

Risperidone

Composition

 

Each film coated tablet contains :

Risperidone .1 , 2 , 3 , 4 mg

 

 Indications

 

Description :

- Risperidone is an oral antipsychotic agent and a first-line option for treating  acute and chronic schizophrenic psychoses.   Advantages over other currently available antipsychotic agents are a reduction in negative symptoms and reduced incidence of extrapyramidal symptoms. Unlike , the  serotonin-dopamine blocking agents marketed, risperidone is not associated with agranulocytosis.

- Risperidone is a selective monoaminergic antagonist with a high affinity for both serotonergic 5-HT2 and dopaminergic D2 receptors. Conventional antipsychotic therapy was based on the assumption that overactive dopaminergic pathways contributed to schizophrenia. Blockade of D2 receptors by conventional antipsychotics alleviates positive symptoms of schizophrenia such as hallucinations, delusions, and erratic behavior and speech. This blockade, however, is considered responsible for the appearance of extrapyramidal symptoms. Serotonin transmission is also thought to be involved in schizophrenia.

- Risperidone is administered orally. Absorption is complete; risperidone can be administered without regard to meals. Peak plasma concentrations are achieved within 1-2 hours. Plasma concentrations are dose-proportional for both the parent compound and the main active metabolite, 9-hydroxy-risperidone. Plasma-protein binding for risperidone and 9-hydroxy-risperidone is 90% and 70%, respectively.

- Risperidone is metabolized by cytochrome P450IID2 enzyme. Both the parent drug and main metabolite are preferentially distributed to the frontal cortex and striatum in the brain, where half-lives are longer than in the plasma. Excretion is mainly renal, with a small amount excreted in the feces. About 90% of an oral dose is eliminated, with a half-life of about 3 hours; half-life of the metabolite is about 24 hours. Renal disease reduces total clearance and prolongs elimination half-life. Reduced dosage levels are indicated in patients with hepatic or renal disease.

 Indications :

- Acute and chronic schizophrenic psychoses for positive, negative and effective symptoms.

 

 

Dosage & Administration

 

Dosage & administration :

Administration

Risperidone is administered orally without regard to meals.

* For the treatment of schizophrenia :

Adults and adolescents: On the first day, 2 mg by oral as a single dose or in two divided doses. Titrate upwards on the second day to 4 mg by oral as a single dose or in two divided doses. On the 3rd day, titrate upwards to 6 mg by oral as a single dose or in two divided doses. Slower titration may be needed in some patients. If further dosage adjustments are indicated, increments or decrements of 2 mg per day at weekly intervals are recommended. In general the effectiveness of doses above 6 mg day have not been demonstrated, and may increase the risk of extrapyramidal symptoms.

Elderly and patients with impaired hepatic function: Initially 0.5 mg by oral twice a day. Increase dosage by 0.5 mg twice a day, with increases above the level of 1.5 mg twice daily only occuring at intervals of one week.

Children under age 15 years: Safe use in children under age 15 years has not been established.

* Patients with renal impairment :

Dosage should be modified depending on clinical response and degree of renal impairment. Initially 0.5 mg by oral twice a day. Increase dosage by 0.5 mg twice a day, with increases above the level of 1.5 mg twice a day only occuring at intervals of one week.

 Contraindications :

Risperidone is contraindicated in :

* Breast-feeding.                     * Children under age 15 years

 Precaution :

Risperidone should be used cautiously in patients with:

- Preexisting hypotension or cerebrovascular disease.

- Cardiac disease, especially those with heart failure, history of myocardial infarction or ischemia, or conduction abnormalities.

- Existent QT prolongation can produce an increased risk of developing arrhythmias.                            - Conditions that may predispose patients to hypotension, such as hypovolemia and dehydration.

As with all schizophrenic patients, possible enhancement of suicidal ideation is a reality in those taking risperidone. Close supervision and control of medication is advisable.

- Parkinson's disease because of possible development of extrapyramidal symptoms.

seizure disorders or brain tumors.

Antiemesis produced by risperidone can obscure evidence of GI obstruction or ileus.

- Breast cancer.

 Drug interaction:

* B-blockers increase risperidone plasma concentrations.

* Carbamazepine or phenobarbital increase the metabolism of risperidone and potentially decrease its effectiveness.

* Cimetidine may increase the risk of developing risperidone-induced extrapyramidal symptoms.

* Risperidone leads to a marked elevation of clozapine serum concentrations.

* Fluoxetine induces tardive dyskinesia.

* Haloperidol the risk of additive toxicity.

* Levodopa & bromocriptine opposites of risperidone.

* Phenothiazines the risk of additive toxicity.

* Tricyclic antidepressants increases in plasma levels of either drug. 

Side effects:

- Abdominal pain          - agitation                    - anxiety

-blurred vision  - constipation               - dizziness

- drowsiness                - dyspepsia                  - dystonic reaction

- ejaculation dysfunction          - fatigue                       - headache

- impotence                 - insomnia                    - libido decrease

- libido increase           - menstrual irregularity            - nausea/vomiting

- neuroleptic malignant syndrome                   - orthostatic hypotension

- parkinsonism - photosensitivity         - QT prolongation

- rhinitis                       - salivation                   - syncope

- ventricular tachycardia           - weight gain                - withdrawal

 Overdosage :

Symptoms :

- Drowsiness and sedation.                  - Tachycardia & hypotension.

- Extra pyramidal symptoms .  - Rarely QT prolongation.

Treatment :

- Adequate oxygenation and ventilation.

- Gastric lavage (if the patient is unconscious)

- Administration of activated charcoal together with laxative.

- There is no specific antidote for Risperidone therefore appropriate supportive measures should instituted :

* hypotension and circulatory collapse should be treated with intravenous fluid and/or sympathomimetic agent.

* In case of sever extra pyramidal symptoms anticholinergic medication should be administered.

* Cardiovascular monitoring should commence immediately and should include continuous ECG monitoring to detect possible arrhythmia.

 Instructions to the patients:

- Risperidone can help you to keep in touch with reality and reduce your mental problems.

- Swallow the tablets with a drink of water. If risperidone upsets your stomach you can take it with food. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.

- Elderly patients over age 65 years may have a stronger reaction to this medicine and need smaller doses.

- Tell your doctor or pharmacist: about all other medicines you are taking, including non-prescription medicines; if you are a frequent user of drinks with caffeine or alcohol; if you smoke; or if you use illegal drugs. These may affect the way your medicine works. Check before stopping or starting any of your medicines.

- Do not suddenly stop taking risperidone. You may need to gradually reduce the dose. Only stop taking risperidone on your doctor's advice.

- You may get dizzy or drowsy. Do not drive, use machinery, or do anything that needs mental alertness until you know how risperidone affects you.Avoid alcoholic drinks. You can get a hangover effect the morning after a bedtime dose.

- Risperidone may make you more sensitive to sun or ultraviolet light. Keep out of the sun, or wear protective clothing outdoors and use a sunscreen (at least SPF 15). Do not use sun lamps, . To protect your eyes wear sunglasses even on cloudy days.

 Pregnency & lactation :

* Risperidone is classified as pregnancy category C.

* The drug is recommended for use during pregnancy only when the benefits outweigh the risks.

* The drug should not be used in breast-feeding women.

 

 

Presentation

 

Risperidone pack of 2 blister X 10 tablets .

Hospital packs of different sizes.

 

 

 

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